rs1555037395

Positions:

• chr11-119344335-G-A

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_031433.4(MFRP):​c.955C>T​(p.Gln319*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 31)
• Consequence: MFRP NM_031433.4 stop_gained
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 1.87

Genes affected

MFRP (HGNC:18121): (membrane frizzled-related protein) This gene encodes a member of the frizzled-related protein family. The encoded protein plays an important role in eye development and mutations in this gene have been associated with nanophthalmos, posterior microphthalmia, retinitis pigmentosa, foveoschisis, and optic disc drusen. The protein is encoded by a bicistronic transcript which also encodes C1q and tumor necrosis factor related protein 5 (C1QTNF5). [provided by RefSeq, Jun 2013]

C1QTNF5 (HGNC:14344): (C1q and TNF related 5) This gene encodes a member of a family of proteins that function as components of basement membranes and may play a role in cell adhesion. Mutations in this gene have been associated with late-onset retinal degeneration. The protein may be encoded by either a bicistronic transcript including sequence from the upstream membrane frizzled-related protein gene (MFRP), or by a monocistronic transcript expressed from an internal promoter. [provided by RefSeq, Jun 2013]

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 11-119344335-G-A is Pathogenic according to our data. Variant chr11-119344335-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 438224.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr11-119344335-G-A is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MFRP	NM_031433.4	c.955C>T	p.Gln319*	stop_gained	8/15	ENST00000619721.6	NP_113621.1
C1QTNF5	NM_015645.5	c.-1682C>T		5_prime_UTR_variant	8/15		NP_056460.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MFRP	ENST00000619721.6	c.955C>T	p.Gln319*	stop_gained	8/15	1	NM_031433.4	ENSP00000481824.1
MFRP	ENST00000360167.4	c.898+297C>T		intron_variant		2		ENSP00000353291.4

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 31

Bravo AF: 0.00000756

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Isolated microphthalmia 5 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 19, 2024

This sequence change creates a premature translational stop signal (p.Gln319*) in the MFRP gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in MFRP are known to be pathogenic (PMID: 12140190, 15976030, 20361016). This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with microphthalmia and retinal dystrophy (PMID: 28041643, 31992737). ClinVar contains an entry for this variant (Variation ID: 438224). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Eurofins Ntd Llc (ga)

Mar 09, 2018

- -

Retinal dystrophy Pathogenic:1

Likely pathogenic, no assertion criteria provided

research

NIHR Bioresource Rare Diseases, University of Cambridge

Jan 01, 2015

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.62
CADD	Pathogenic	45
DANN	Uncertain	1.0
Eigen	Pathogenic	0.71
Eigen_PC	Uncertain	0.52
FATHMM_MKL	Uncertain	0.92	D
Vest4		0.69
GERP RS		3.8

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.21		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.21		Position offset: -20

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs1555037395; hg19: chr11-119215045;